Population Balance Models: A useful complementary modelling framework for future WWTP modelling

Population Balance Models (PBMs) represent a powerful modelling framework for the description of the dynamics of properties that are characterised by statistical distributions. This has been demonstrated in many chemical engineering applications. Modelling efforts of several current and future unit processes in WWTPs could potentially benefit from this framework, especially when distributed dynamics have a significant impact on the overall unit process performance. In these cases, current models that rely on average properties cannot sufficiently captured the true behaviour. Examples are bubble size, floc size, crystal size or granule size,... PBMs can be used to provide new insights that can be embedded in our current models to improve their predictive capability. This paper provides an overview of current applications and the future potential of PBMs in the field of WWT modelling, introducing new insights and knowledge from other scientific disciplines.